Welding operations are routinely performed on various types of items, such as automobile engine blocks, in order to effect repairs. Due to the geometric configuration of these items and/or the particular alloys from which they are made, localized heating of certain portions of the workpiece may result in irreparable damage to the workpiece; for example, localized heating of an engine block may result in warpage or cracking of cylinder walls.
It is therefore often necessary to preheat the workpiece before the welding operations are performed. Heretofore, it was necessary to place the workpiece in an oven for the preheating operation following which the preheated workpiece was removed from the oven and the welding was performed. However, the duration for which welding could be continued was limited since the workpiece began cooling as soon as it was removed from the oven.
The task of designing a furnace within which welding operations might be performed is complicated by the fact that some workpieces are relatively heavy and access must be had to virtually all points on the workpiece through the furnace.
Accordingly, it is a primary object of the present invention to provide a welding furnace which preheats a workpiece to be welded and allows the workpiece to be welded within the furnace.
A further object of the invention is to provide a welding furnace of the type mentioned above which permits convenient access to virtually all locations on the workpiece.
A still further object of the invention is to provide a welding furnace similar to that described above which is readily portable and is adapted to accommodate a wide range of workpieces.